Diene copolymer including at least two blocks, method for synthesizing same and rubber composition containing same
A process for the synthesis of a diene copolymer comprising at least two blocks, at least one of the blocks being composed of a diene elastomer, characterized in that it comprises a stage of 1,3-dipolar reaction of two polymers defined as being: a) a diene elastomer bearing an alkyne functional group at one or each of its chain ends, and b) a polymer bearing at least one azide functional group. This process of synthesis can be adjusted, whatever the nature of the monomers necessary to form each of the blocks of the copolymer. Each block can be synthesized with an appropriate chemistry, independently of the other block.
1. A diene copolymer comprising at least two blocks, at least one of the blocks being composed of a diene elastomer, comprising at least one sequence corresponding to the following formula:
P-L-E
wherein:
P denotes a polymer,
E denotes a diene elastomer,
L is a divalent hydrocarbon group corresponding to one of the following formulae D1 and F1:
wherein:
R 1 and R 2 , and also R 3 and R 4 , which can be borne by the ortho, meta or para position, denote, independently of one another, a hydrogen atom, a C 1 -C 15 alkyl group, a C 5 -C 15 cycloalkyl group, a C 6 -C 15 aryl group or a C 7 -C 15 arylalkyl group which can be separated from the aromatic nucleus by a heteroatom,
R 5 , denotes a hydrogen atom, a C 1 -C 5 alkyl group, a cycloalkyl group, a C 6 -C 15 aryl group, a C 7 -C 15 arylalkyl group or a protective group for alkyne functional groups,
* indicates a point of bonding to an E block of the copolymer which is located in the ortho, meta or para position with respect to the triazolediyl group, and
** indicates a point of bonding to a P block of the copolymer.
2. The block diene copolymer according to claim 1 , which corresponds to the formula:
(P-L-E) n -X
wherein:
P denotes a polymer,
E denotes a diene elastomer,
L is a divalent hydrocarbon group corresponding to one of the following formulae D1 and F1:
wherein:
R 1 and R 2 , and also R 3 and R 4 , which can be borne by the ortho, meta or para position, denote, independently of one another, a hydrogen atom, a C 1 -C 15 alkyl group, a C 5 -C 15 cycloalkyl group, a C 6 -C 15 aryl group or a C 7 -C 15 arylalkyl group which can be separated from the aromatic nucleus by a heteroatom,
R 5 , denotes a hydrogen atom, a C 1 -C 5 alkyl group, a cycloalkyl group, a C 6 -C 15 aryl group, a C 7 -C 15 arylalkyl group or a protective group for alkyne functional groups,
* indicates a point of bonding to an E block of the copolymer which is located in the ortho, meta or para position with respect to the triazolediyl group,
** indicates a point of bonding to a P block of the copolymer, and
X denotes a mono- or polyvalent radical chosen from a C 1 -C 15 alkyl radical, a C 5 -C 15 cycloalkyl radical, a C 6 -C 15 aryl radical, a C 7 -C 15 arylalkyl radical or a radical resulting from a functionalization, coupling or star-branching agent comprising at least one atom chosen from O, N, Si or Sn, and
n is an integer ranging from 1 to 12.
3. The block diene copolymer according to claim 1 , which corresponds to the formula:
(X-E-L) m -P
wherein:
P denotes a polymer,
E denotes a diene elastomer,
X denotes a monovalent radical chosen from a C 1 -C 15 alkyl radical, a C 5 -C 15 cycloalkyl radical, a C 6 -C 15 aryl radical, a C 7 -C 15 arylalkyl radical, or a radical resulting from a functionalization agent comprising at least one atom chosen from O, N, Si or Sn;
m is an integer ranging from 1 to 12; and
L is a divalent hydrocarbon group corresponding to one of the following formulae D1 and F1:
wherein:
R 1 and R 2 , and also R 3 and R 4 , which can be borne by the ortho, meta or para position, denote, independently of one another, a hydrogen atom, a C 1 -C 15 alkyl group, a C 5 -C 15 cycloalkyl group, a C 6 -C 15 aryl group or a C 7 -C 15 arylalkyl group which can be separated from the aromatic nucleus by a heteroatom,
R 5 , denotes a hydrogen atom, a C 1 -C 5 alkyl group, a cycloalkyl group, a C 6 -C 15 aryl group, a C 7 -C 15 arylalkyl group or a protective group for alkyne functional groups,
* indicates a point of bonding to an E block of the copolymer which is located in the ortho, meta or para position with respect to the triazolediyl group, and
** indicates a point of bonding to a P block of the copolymer.
4. The block diene copolymer according to claim 1 , wherein E is selected from the group consisting of polybutadienes (BRs), synthetic polyisoprenes (IRs) butadiene/styrene copolymers (SBRs), isoprene/butadiene copolymers (BIRs), isoprene/styrene copolymers (SIRs) and isoprene/butadiene/styrene copolymers (SBIRs).
5. The block diene copolymer according to claim 1 , wherein P is a diene elastomer, a polyacrylate or a polystyrene.
6. A rubber composition based (1) on an elastomer matrix comprising at least one block diene copolymer and (2) on a reinforcing filler, the at least one block diene copolymer comprising at least one sequence corresponding to the following formula:
P-L-E
wherein:
P denotes a polymer,
E denotes a diene elastomer,
L is a divalent hydrocarbon group corresponding to one of the following formulae D1 and F1:
wherein:
R 1 and R 2 , and also R 3 and R 4 , which can be borne by the ortho, meta or para position, denote, independently of one another, a hydrogen atom, a C 1 -C 15 alkyl group, a C 5 -C 15 cycloalkyl group, a C 6 -C 15 aryl group or a C 7 -C 15 arylalkyl group which can be separated from the aromatic nucleus by a heteroatom,
R 5 , denotes a hydrogen atom, a C 1 -C 5 alkyl group, a cycloalkyl group, a C 6 -C 15 aryl group, a C 7 -C 15 arylalkyl group or a protective group for alkyne functional groups,
* indicates a point of bonding to an E block of the copolymer which is located in the ortho, meta or para position with respect to the triazolediyl group, and
** indicates a point of bonding to a P block of the copolymer.
7. A vehicle tire, one of the constituent components of which comprises a rubber composition as defined in claim 6 .